Once your sod has been installed you should begin watering immediately. For the first week water daily. Water every section of your new lawn in half hour cycles twice a day. If you notice mushrooms don't panic this is a sign of over watering. Cut down the cycles, 15 or 20 minutes should do the trick depending on the weather.
You lawn will turn brown and have a resemblance to straw if not watered properly.
Once you lawn is established you will have to use your own judgment when it comes to watering. Remember watering depends on temperature and rain fall.